TV best bets: Thursday, May 1

The Record

8 p.m., NBC: IHeartRadio Music Awards — The IHeartRadio digital audio service honors the most popular musical performers and performances of the past year as determined by its own charts tracking airplay, downloads, sales, social media exposure and more. Rihanna, Justin Timberlake, Imagine Dragons, Maroon 5, and Macklemore & Ryan Lewis are vying for artist of the year.

10 p.m., ABC: Black Box — Catherine’s (Kelly Reilly) team of medical students tries to diagnose a young nanny who’s having hallucinations of her head exploding. Will (Dave Ajala) deals with the revelation that Catherine cheated on him during a manic episode. After the chief of neurosurgery has a seizure in the OR, the Cube’s medical director announces that doctors with potentially harmful medical conditions must come forward in the new episode "Sweet Little Lies."

10 p.m., HISTORY CHANNEL: Vikings — A final showdown is near as Ragnar and King Horik (Travis Fimmel, Donal Logue) return to Kattegat. Ragnar realizes that he has placed his trust in those who have stood by him, and it’s time to consider forging some new alliances. Katheryn Winnick and Clive Standen also star in the season finale, "The Lord’s Prayer."

TV best bets: Thursday, May 1

The Record

8 p.m., NBC: IHeartRadio Music Awards — The IHeartRadio digital audio service honors the most popular musical performers and performances of the past year as determined by its own charts tracking airplay, downloads, sales, social media exposure and more. Rihanna, Justin Timberlake, Imagine Dragons, Maroon 5, and Macklemore & Ryan Lewis are vying for artist of the year.

10 p.m., ABC: Black Box — Catherine’s (Kelly Reilly) team of medical students tries to diagnose a young nanny who’s having hallucinations of her head exploding. Will (Dave Ajala) deals with the revelation that Catherine cheated on him during a manic episode. After the chief of neurosurgery has a seizure in the OR, the Cube’s medical director announces that doctors with potentially harmful medical conditions must come forward in the new episode "Sweet Little Lies."

10 p.m., HISTORY CHANNEL: Vikings — A final showdown is near as Ragnar and King Horik (Travis Fimmel, Donal Logue) return to Kattegat. Ragnar realizes that he has placed his trust in those who have stood by him, and it’s time to consider forging some new alliances. Katheryn Winnick and Clive Standen also star in the season finale, "The Lord’s Prayer."